The present invention relates generally to a solid state system for providing illumination from an external light source through an instrument to an object, such as a patient surgical site. The external light source includes components for providing light in the visible spectrum as well as light in the infrared spectrum.
Endoscopic systems are used to inspect regions within a body during surgery. Endoscopic systems typically include an endoscope, a light source, and an imaging device such as a camera head. Typically, an endoscope includes a rigid or flexible elongated insertion tube equipped with a set of optical fibers that extend from a proximal handle through the endoscope body to a distal viewing tip. An external light source provides light to the optic fibers via a cable that attaches to a post or other structure on the endoscope. The endoscope also receives images and transmits them to the imaging device for providing a image to a monitor or other display apparatus for viewing by a surgeon.
In one commercial embodiment, an endoscopic system includes a solid state light source that generates white light which is conveyed to a distal end of the endoscope via a light guide. The light guide includes multiple fibers and is connected between an output connector of the light source and a light post of the endoscope. The white light illuminates a working area at the distal end of the endoscope. The camera, connected to a handle of the endoscope, generates video signals representative of images at the working area for display on a video monitor.
The light source includes an optical system and a lens array used to collimate light from an LED array. A focusing lens focuses the light onto the light guide. The lenses collect light emitted by LEDs. The lenses may be single lenses, such as single or double aspherics, compound lenses, radiant index type lenses, or combinations of each of these. Other arrangements have lens arrays that are implemented as part of an LED array by adhesion, fusion, or other means. Some arrangements have a rectangular-shaped LED and lens array.
The focal length of the lens and the diameter of the lenses are chosen on the order of a few millimeters. The actual values are selected based on the size of the LED emitting surface which determines the field of view of the lens.
The collected light from the lens array travels to a focusing lens. The focusing lens projects the image of each LED light emitting surface onto an entrance face of the light guide. The image is magnified so that the size is approximately equal to the size of the entrance face of the light guide. The light guide transports the light to the endoscope. The light passes through the endoscope to illuminate a surgical site. Light is reflected off of the surgical site which is received by the endoscope and transmitted to the camera head. The camera head provides images of the surgical site for display on the monitor.
Another endoscopic system that has been designed is described in commonly-owned PCT Application No. WO 2010/059197 A2, which is incorporated in its entirety by reference.
The above-described endoscopic systems do not concern themselves with the ability of excitation of fluorescent markers in an object, such as a body part at a surgical site. While there are systems on the market that do provide excitation light for fluorescent markers, these systems typically use multiple light sources and multiple components to transmit infrared light to the surgical site, and multiple components to separate the fluorescent light emitted by the fluorescent markers. The present invention is a solution to those problems.
One embodiment of the present invention includes a single light source which is capable of providing white light, i.e. light in the visible spectrum, and providing infrared light capable of exciting fluorescent markers at a surgical site through an endoscope. The endoscope is also capable of receiving reflected light from the surgical site and fluorescent light emitted from the fluorescent markers.
Another embodiment of the invention employs a light source to provide light in the red, blue, green, and infrared wavelength spectra to an endoscope which transports the light to a surgical site. Reflected light and fluorescent light from fluorescent markers at the surgical site are then transmitted through the endoscope, through a notch filter, and then to a trichroic prism for separation into light in the infrared spectrum, light in the blue spectrum, and light in the green spectrum.
Other advantages, objects and/or purposes of the invention will be apparent to persons familiar with constructions of this general type upon reading the following specification and inspecting the accompanying drawings.